Flow batteries - Impact on fire safety

Abstract

The need for sustainable renewable energy has been increasing due to the negative impact of non-renewable energy sources. With the unstable and sporadic nature of sustainable renewable energy, flow batteries show immense potential in mitigating these issues. Traditional vanadium and zinc-based flow batteries, as well as new flow battery systems, are now being researched extensively. Vanadium and zinc-based flow batteries are nearing commercialization, but their low power and energy densities keep them from being used in more businesses and industries.

This thesis examines the effect of flow batteries on fire safety since battery storage systems have become more popular as a form of energy storage. A literature review is undertaken using the key terms listed below to locate current articles, journals, and research papers that give the most comprehensive answers to flow battery-related concerns. The first section of the thesis discusses the necessity for energy storage systems and how flow batteries may be incorporated into them. The second section discusses the operating principle and idea of a flow battery. The thesis's second half discusses the safety and fire issues connected with flow batteries, including gas development, thermal runaway, and deterioration. These risks are contrasted to those associated with lithium-ion batteries to demonstrate how each storage solution might contribute to fire safety.

Popular Abstract

The detrimental effect of nonrenewable energy sources has increased the need for sustainable renewable energy. However, reliance on renewable energy sources also necessitates the existence of a feasible energy storage system, such as a battery energy storage system, which acts as a tool for storing, delivering, and distributing electrical energy. This kind of energy storage technology delivers great efficiency by enhancing the grid's resilience and dependability and reducing our reliance on fossil fuel-based energy sources.

This thesis will investigate the impact of flow batteries on fire safety since battery storage systems have become an increasingly common method of energy storage. The literature review is conducted to comprehend the safety and fire concerns associated with flow batteries. Even though flow batteries are regarded to be intrinsically safer than typical lithium-ion batteries, there are various scenarios in which flow batteries might offer a substantial threat, and this thesis analyzes these discoveries.

In the review, a semi-systematic technique or a narrative review methodology was developed, and 110 publications were analyzed; these papers were screened based on a set of inclusion/exclusion criteria, with fire and safety concerns taking precedence. After evaluating the safety problems and fire threats connected with flow batteries, the hazards are compared to those of lithium-ion batteries, which are now the market leader in terms of battery storage systems but are deficient in terms of fire and safety concerns.

Flow batteries have been proven to provide considerable advantages over lithium-ion batteries in terms of safety, scalability, and possibly a longer life cycle. However, the fact that it is safer than lithium-ion does not imply that it is entirely safer since it has several disadvantages, such as electrolyte leakage and gas evolution owing to side reactions. Flow batteries employ a non-flammable electrolyte because the bulk of the electrolyte in flow batteries is water, while lithium-ion batteries use a flammable electrolyte. The second safety feature of flow batteries is that they employ pumps to circulate the electrolyte into the reaction region where current is produced. By reversing the flow of the pumps, the electrolyte may be drained from the reaction area, eliminating any current/voltage hazards or reducing any potentially arising hazard. Flow batteries can be dangerous because they need to store a large quantity of electrolytes to produce enough energy, and because they need a lot of complicated mechanical and electrical parts, like valves, pipes, pumps, and inverters, to work well together, there is always a chance that electrolyte will leak, or parts might fail. Even though the electrolytes used are not flammable, it is very acidic, which causes toxicity and corrosivity problems. Both vanadium flow batteries and zinc-bromine flow batteries employ sulfuric acid and bromine as supporting electrolytes respectively, which are believed to be powerful oxidizers that promote the burning of other substances. Other hazards observed were the risk of gas evolution such as hydrogen during normal operations induced by cell imbalance inside the battery; without sufficient venting/safety procedures, hydrogen gas can quickly approach its flammable limits. If a secondary fire threatens the storage system, both lithium-ion batteries and flow batteries may represent a serious hazard to life and property, since an explosion is a potential possibility.

• author: Menon, Ajay
• supervisor: Petra Andersson
• organization: Division of Fire Safety Engineering
• course: VBRM05 20221
• year: 2022
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: Flow battery, Flow battery types, Flow battery risks, Firefighting, Fire risk analysis, Safety hazards in flow batteries, Fire risks in lithium-ion battery, Safety hazard in lithium-ion battery, Application of battery storage systems, Safety reports.
• publication/series: LUTVDG/TVBB
• report number: 5671
• other publication id: LUTVDG/TVBB—5671—SE
• language: English
• id: 9084733
• date added to LUP: 2022-06-07 15:26:29
• date last changed: 2022-06-07 15:26:29